A general purpose wideband optical spatial frequency spectrum analyzer

The light scattered at various angles by a transparent media is studied. An example of these applications is the optical Fourier spectrum measurement resulting from various spatial frequencies which were recorded on a photographic emulsion. A method for obtaining these measurements consists of illuminating the test object with parallel monochromatic light. A stationary lens, placed in the resulting wavefield at a distance of one focal length from the object, will focus parallel waves emanating from the test object at a point lying in the focal plane of the lens. A light detector with a small filtering aperture is then used to measure the intensity variation of the light in the focal or transform plane of the lens. Such measurements require the use of a lens which is highly corrected for all of the common aberrations except chromatic aberration

A method of calculating compressible turbulent boundary layers

Equations of motion for calculating compressible turbulent boundary layer

Computer program for calculating laminar and turbulent boundary layer development in compressible flow

A computer program is described which performs a numerical integration of the equations of motion for a compressible two-dimensional boundary layer. Boundary layer calculations may be carried out for both laminar and turbulent flow for arbitrary Reynolds number and free stream Mach number distribution on planar or axisymmetric bodies with wall heating or cooling, longitudinal wall curvature, wall suction or blowing, and a rough or a smooth wall. A variety of options are available as initial conditions. The program can generate laminar initial conditions such as Falkner-Skan similarity solutions (so that initial wedge flows can be simulated including Blasius or stagnation point flow) or approximate equilibrium turbulent profiles. Alternatively, initial profile input data can be utilized

The development of mission theology and praxis at Cliff College, with reference to its antecedents and history.

A thesis submitted for the degree of Doctor of Philosophy in the department of Theology and Religion, Faculty of Arts, Durham University 2005.This thesis is an examination and evaluation of evangelistic ministry at Cliff College and its major themes, or Charisms. It charts the rise of the College and its antecedents in section one, introducing the main characters and events. Section two introduces themes that have shaped the tradition of the College; the most significant being holiness teaching which finds its origins in the works of John Wesley. Though they differed in emphasis, most Principals were proponents of this doctrine. There developed at the College a theology which was biblical and evangelical but not fundamentalist or sectarian. The College espoused 'faith principles' but ensured supporters were aware of its needs. The College is known primarily for training people in evangelism. Section three charts this innovative ministry beginning with the joyful News Mission and continuing through the years of Cook, Chadwick and Broadbelt. Between 1939 and the late 1950s there was a dearth of creative thinking about evangelism. Meadley and Beiben laid the foundations that, in the late 1970s, gave rise to a new strategy which was given impetus through the 1980s. The innovative thinking of the first period is illustrated by reference to the Joyful News female evangelists and the trekkers. Section four examines the particular academic stance taken by College Principals. This was specifically to offer training, focussed on evangelistic ministry, to those who may not otherwise have the opportunity. A policy of open access was retained throughout, with the College seeking proper recognition. This eventually came with the validation of the College programmes by the University of Sheffield. Chapter eleven charts the emergence of missiology as a discipline in the academy. The conclusion identifies the ambivalent attitude of Methodism to the College, and that its major charisms continue to have a significant influence though in need of constant restatement

High-resolution 3D weld toe stress analysis and ACPD method for weld toe fatigue crack initiation

Weld toe fatigue crack initiation is highly dependent on the local weld toe stress-concentrating geometry including any inherent flaws. These flaws are responsible for premature fatigue crack initiation (FCI) and must be minimised to maximise the fatigue life of a welded joint. In this work, a data-rich methodology has been developed to capture the true weld toe geometry and resulting local weld toe stress-field and relate this to the FCI life of a steel arc-welded joint. To obtain FCI lives, interrupted fatigue test was performed on the welded joint monitored by a novel multi-probe array of alternating current potential drop (ACPD) probes across the weld toe. This setup enabled the FCI sites to be located and the FCI life to be determined and gave an indication of early fatigue crack propagation rates. To understand fully the local weld toe stress-field, high-resolution (5 mu m) 3D linear-elastic finite element (FE) models were generated from X-ray micro-computed tomography (mu-CT) of each weld toe after fatigue testing. From these models, approximately 202 stress concentration factors (SCFs) were computed for every 1 mm of weld toe. These two novel methodologies successfully link to provide an assessment of the weld quality and this is correlated with the fatigue performance

A theological examination of the non-directive approach to church and community development with a special reference to the nature of evangelism

.A thesis submitted for the degree of Master of Arts in Theology in the Theology Department, Faculty of Arts, University of Durham 1990.This thesis is an examination of the nature and value of the non-directive approach to church and community work. Special attention is paid to the suitability of the approach in the context of evangelical ministry. The thesis originates out of my seven years of pastoral ministry in Addiscombe Croydon. For many years I had been committed to an evangelistic ministry; this thesis describes the process of adopting a non-directive approach to that ministry, first of all intuitively and then systematically. The thesis charts the origins and rise of community development and the non- directive approach. It appropriates more recent discussion of the relationship between community work and community development. It then shows the adoption of community development ideas by a number of Christians and considers the nature of the directive and non-directive approaches and their application. Evangelistic ministry is analyzed by noting the characteristics common to all evangelicals and then constructing in some detail a typology of evangelicals against which to test the applicability of the non-directive approach. The thesis then sets out and critically reviews the theology of church and community development It tests out the non-directive against the biblical narrative, considering Jesus use of parable; the exercise of authority, and use of charismatic gifts within the church. It then examines three areas which seem predisposed to show dissonance between evangelistic ministry and the non-directive approach; decision-making, theology of evangelical conversion, and proclamation of the evangel. The thesis finds the biblical teaching supports the non-directive, whilst also recognizing certain aspects as non-negotiable. The thesis concludes that only one type of evangelical, fundamentalist evangelical, is incompatible with the non-directive approach. All the other types of evangelicals are capable of adopting this approach. It further concludes that the non-directive approach is not only consonant with evangelistic ministry but could be a vital partner to such a ministry and increase its effectiveness

Oxygen/Glucose deprivation induces a reduction in synaptic AMPA receptors on hippocampal CA3 neurons mediated by mGluR1 and adenosine A3 receptors

Hippocampal CA1 pyramidal neurons are highly sensitive to ischemic damage, whereas neighboring CA3 pyramidal neurons are less susceptible. It is proposed that switching of AMPA receptor (AMPAR) subunits on CA1 neurons during an in vitro model of ischemia, oxygen/glucose deprivation (OGD), leads to an enhanced permeability of AMPARs to Ca2+, resulting in delayed cell death. However, it is unclear whether the same mechanisms exist in CA3 neurons and whether this underlies the differential sensitivity to ischemia. Here, we investigated the consequences of OGD for AMPAR function in CA3 neurons using electrophysiological recordings in rat hippocampal slices. Following a 15 min OGD protocol, a substantial depression of AMPAR-mediated synaptic transmission was observed at CA3 associational/commissural and mossy fiber synapses but not CA1 Schaffer collateral synapses. The depression of synaptic transmission following OGD was prevented by metabotropic glutamate receptor 1 (mGluR1) or A3 receptor antagonists, indicating a role for both glutamate and adenosine release. Inhibition of PLC, PKC, or chelation of intracellular Ca2+ also prevented the depression of synaptic transmission. Inclusion of peptides to interrupt the interaction between GluA2 and PICK1 or dynamin and amphiphysin prevented the depression of transmission, suggesting a dynamin and PICK1-dependent internalization of AMPARs after OGD. We also show that a reduction in surface and total AMPAR protein levels after OGD was prevented by mGluR1 or A3 receptor antagonists, indicating that AMPARs are degraded following internalization. Thus, we describe a novel mechanism for the removal of AMPARs in CA3 pyramidal neurons following OGD that has the potential to reduce excitotoxicity and promote neuroprotectio

Gravitational quasinormal modes for Anti-de Sitter black holes

Quasinormal mode spectra for gravitational perturbations of black holes in four dimensional de Sitter and anti-de Sitter space are investigated. The anti-de Sitter case is relevant to the ADS-CFT correspondence in superstring theory. The ADS-CFT correspondence suggests a prefered set of boundary conditions.Comment: 12 pages, 6 figures in ReVTe